This invention relates to hair processing methods and apparatus to apply or transform permanent waves or related styles of hair, and more particularly to a method and apparatus which are based on the fact that essential characteristics of hair are changed by applying a predetermined pressure or certain pressure and heat to the hair, and which enables permanent wave shrunken or curled hair to be transformed into straight hair, to hair straightened by chemical process into waved hair, or make fine split hair back to the original state, and also enables to maintain processed states of straight, waved or treated hair for a long time.
Human hair, like skin and nails, consists of fibrous proteins known as keratins. Keratins are made up of coiled polypeptide chains combined to form supercoils of several polypeptides linked by disulfide bonds between adjacent amino acids. Aggregates of these supercoils form microfibrils, which are embedded in a protein matrix.
When analyzed on a individual structual basis, each hair is composed of a medullar (core) as its center, cortices which surround the medullar (the cortices are formed of longitudinally arranged spindle or cigar like shaped outer layer cells filled with keratin fibers), matrices which connects the cortex (outer layer) to each other (the matrices called padding material, have higher water absorption and moisture retention properties), and cuticles (outer layer of the hair) which surround the hair.
Therefore, to keep hair healthy for a long time, it is recommended to ingest adequate protein levels to provide enough to the body for forming keratin.
However, since hair is exposed to open air and sun light, and receives substances floating in the air, ingesting adequate protein as explained before does not suffice for ideal health of the hair. It is further recommended to make efforts to carry out hair health care by diligent shampoo and treatment of the hair.
For the purposes of this application, the term "permanent wave", which is a term of art, is defined as "Artificial waves in the hair produced by applying chemicals to it while wet, winding it on curlers, and drying it with heat." (The American Heritage Dictionary, Fourth College Edition, Houghton Mifflin Company, Boston--1991, at page 924). The noun form of this term may alternatively be utilized, and it is abbreviated herein as "perm". The term applies both to chemical treatments to impart and remove "waves" from the hair.
In a conventional processing of straight perm or wave perm, hair is washed and kept clean, and, a softening process (a first liquid process) is performed by applying or coating softening material such as a cold liquid onto the whole hair. Then, the whole hair is divided into some bundles, and, for each bundle, a heating process, combing process, deposition of creamy material, or rolling by a rod is performed (for wave perm). Next, a hardening process (a second liquid process) is performed by applying or coating hardening material such as a cold liquid. After a certain time period, if necessary, rods are removed, and the hair is processed with hot water rinse to finalize straight perm, wave perm or hair treatment.
The conventional straight perm, wave perm and hair treatment processes are performed by so called chemical steps only. That is, the stiffness of hair is changed by infiltrating the cold liquids (the first and second liquids) into matrices and cuticles portions of hair, and, during that process, the heating, combing, depositing or rolling process is performed for straight, wave perm or hair treatment. For that reason, the retention time of straight, wave perm and hair treatment is short.
According to conventional belief hair processing is time limited, and shape retention gradually degrades over time. Time for infiltrating cold liquids is limited in the above mentioned process (long time process involves significant damage to hair health condition), and it is impossible to infiltrate cold liquids into matrices and cuticles adequately. Further, frequent shampoo washes out the cold liquids and the hair tends to return to the original state. Thus the shape retention effect of straight or wave perm or hair treatment is gradually lost.
In order to improve the shape retention effect of the cold liquids, pH of the cold liquids (the first and second liquid) is, for example, adapted for each person according to her or his hair characteristics. However, adequate shape retention effects still have not been achieved according to known practice.
As a prior art means for heating hair, a heating iron having contact faces, which are formed in a shape such as a wave, was developed. In process of wave perm or the like with that iron, a bundle of hair is supported with one hand and the iron is held with the other hand. The bundle of hair is nipped between a pair of facing surface of the iron and the bundle of hair obtains the shape of the facing surface of the iron. The process is primarily based on the heating iron, and the object of the pressure applied to the hair while the hair nipped with the iron is to hold the hair. Therefore that process is completely different from hair processing of wave perm or the like, which will be clearly disclosed below. In other words, applications of pressure, based upon the structural characteristics of hair, have generally not be utilized in conventional hair processing techniques for to apply or transform permanent waves or related styles of hair.